Do you mean bare bones no cash for big output cheap food?
or do you mean "I can swing a big initial output of money to save tons"?
If its the first one, find a dollar general with a fridge/frozen food section. You can make quite a few good, low intiail cost meals from what you can get from there.
if you mean "I can swing a big upfront payout to get a lot of stuff thats bargain barrel price per unit", then buying a whole pig or cow and having it butchered is probably the best way to get a ton of meat, dollar per pound wise.